How to Reverse Engineer Laifeng Live Chat API and Send Automated Messages with Python

This article presents a step‑by‑step tutorial for a web‑scraping project that automates sending chat messages on the Laifeng live‑streaming platform. It explains how to navigate to the target site, enter a live room, log in, and capture the network packet that carries a comment.

Analysis (x0)

After logging in, the captured request contains roomid (the live‑room identifier) and content (the message). The roomid can be read from the URL, while the t parameter is a timestamp generated by JavaScript new Date().getTime(). The sign parameter is a JavaScript‑generated signature that also depends on the timestamp.

Analysis (x1)

The timestamp t is simply the current Unix time in milliseconds. In Python it can be reproduced with:

import time
t = str(int(time.time() * 1000))

To compute sign, the original JavaScript code is examined. It uses a series of bitwise operations (functions h, i, j, k) similar to an MD5‑like algorithm. By loading the JavaScript file with execjs, the same function can be called from Python.

Analysis (x2)

Further debugging shows that the request also includes a constant appKey, a dictionary c whose data field contains the JSON payload, and a token value that is actually stored in the cookies. All these values are assembled into the final GET request URL that carries t and sign.

Code

import requests
import execjs
import time

ck = 'YOUR_COOKIE_STRING'
headers = {
    'authority': 'www.laifeng.com',
    'method': 'GET',
    'path': '/?',
    'scheme': 'https',
    'accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9',
    'accept-encoding': 'gzip, deflate, br',
    'accept-language': 'zh-CN,zh;q=0.9,en-US;q=0.8,en;q=0.7',
    'cache-control': 'no-cache',
    'cookie': ck,
    'pragma': 'no-cache',
    'sec-ch-ua-mobile': '?0',
    'sec-fetch-dest': 'document',
    'sec-fetch-mode': 'navigate',
    'sec-fetch-site': 'none',
    'sec-fetch-user': '?1',
    'upgrade-insecure-requests': '1',
    'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.25 Safari/537.36 Core/1.70.3870.400 QQBrowser/10.8.4405.400'
}

# Step 1: Get homepage (optional)
url = 'https://www.laifeng.com/'
requests.get(url, headers=headers)

# Step 2: Access a specific live room
room_id = '711329'
url = f'https://v.laifeng.com/{room_id}'
requests.get(url, headers=headers)

# Step 3: Generate timestamp and signature
t = str(int(time.time() * 1000))
with open('js1.js', 'r', encoding='utf-8') as f:
    ctx = execjs.compile(f.read())
sign = ctx.call('test', '{"roomId":"711329","content":"Test message"}', t)

# Step 4: Send the comment
post_url = f'https://acs.laifeng.com/h5/mtop.youku.live.platform.chat/1.0/?jsv=2.6.1&appKey=24679788&t={t}&sign={sign}&type=originaljson&dataType=json&api=mtop.youku.live.platform.chat&v=1.0&ecode=1'
post_data = {'data': '{"roomId":"711329","content":"Test message"}'}
post_headers = {
    'authority': 'acs.laifeng.com',
    'method': 'POST',
    'path': f'/h5/mtop.youku.live.platform.chat/1.0/?jsv=2.6.1&appKey=24679788&t={t}&sign={sign}&type=originaljson&dataType=json&api=mtop.youku.live.platform.chat&v=1.0&ecode=1',
    'scheme': 'https',
    'accept': 'application/json',
    'accept-encoding': 'gzip, deflate, br',
    'accept-language': 'zh-CN,zh;q=0.9,en-US;q=0.8,en;q=0.7',
    'cache-control': 'no-cache',
    'content-length': '65',
    'content-type': 'application/x-www-form-urlencoded',
    'cookie': ck,
    'origin': 'https://v.laifeng.com',
    'pragma': 'no-cache',
    'referer': f'https://v.laifeng.com/{room_id}',
    'sec-ch-ua-mobile': '?0',
    'sec-fetch-dest': 'empty',
    'sec-fetch-mode': 'cors',
    'sec-fetch-site': 'same-site',
    'user-agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.25 Safari/537.36 Core/1.70.3870.400 QQBrowser/10.8.4405.400'
}
response = requests.post(post_url, headers=post_headers, data=post_data)
print(response.text)

Result

The script successfully sends a comment to the specified live room. The response from the server confirms that the request was accepted.

Original source: blog.csdn.net/Python_shannian/article/details/120059842